Unsaturated carboxylic acid amide compounds have been produced typically by methods in which an unsaturated carboxylic acid is dehydratively condensed with an amine. Patent Literature (PTL) 1 describes a method for producing 2-hydroxycinnamamide. In the method, 2-hydroxycinnamic acid is dehydratively condensed with an amine using carbodiimide as a dehydrating-condensing agent. Non Patent Literature (NPL) 1 describes a method for producing 4-methoxycinnamamide. In the method, 4-methoxycinnamic acid is dehydratively condensed with an amine using N,N-carbonyldiimidazole as a dehydrating-condensing agent. Unfortunately, the dehydrating-condensing agents used in the methods are expensive and may cause a severe allergic reaction. Alternatively, such unsaturated carboxylic acid amide compounds have been produced by a method of hydrating an unsaturated carboxylic acid nitrile. Disadvantageously, the method suffers from deterioration in reaction selectivity in some kinds of the unsaturated carboxylic acid moiety. For these reasons, the above-mentioned methods are employed with difficulty as methods for industrially producing unsaturated carboxylic acid amide compounds.
Under such circumstances, unsaturated carboxylic acid amide compounds are synthetically prepared most generally by methods in which an unsaturated carboxylic acid is allowed to react with thionyl chloride to give an unsaturated carboxylic acid chloride, and the prepared unsaturated carboxylic acid chloride is allowed to react with an amine. In a method described in NPL 2, an unsaturated carboxylic acid is mixed with thionyl chloride in an amount 8.6 times the mole of the unsaturated carboxylic acid with cooling and, after the initiation of reaction, the mixture is heated to reflux to give an unsaturated carboxylic acid chloride. However, an unsaturated carboxylic acid amide compound prepared by the method included large amounts of organochlorine compounds derived from thionyl chloride.
Independently, high-performance (highly functional) materials include photosensitive high-performance materials (resist materials) for use in the production of electrical and electronic components. Among them, those requiring particularly high reliability include semiconductor encapsulating materials, packaging materials typically for semiconductor devices and MEMS (micro electro mechanical systems), and photosensitive materials for semiconductor devices, liquid crystal displays, and MEMS. These materials should include ingredients with higher and higher purity. Of impurities or by-products, chlorine-containing compounds are known to significantly affect the performance of electrical and electronic components. PTL 2 discloses that a halogen atom contained in by-products becomes a halogen anion upon exposure (light irradiation), thus reduces the effect of an acid generator, and lowers the sensitivity. PTL 3 discloses as follows. Assume that a compound contains, as impurities, large amounts of organochlorine compounds such as hydrolyzable chlorine that liberates a chlorine ion upon moisture absorption. This compound, when used in the production of an electrical/electronic component, causes the electrical/electronic component to be susceptible to corrosion and/or a break of interconnections and deterioration in insulation quality and to have inferior reliability.
To prevent this, demands have been made to provide a method for producing a crystal including a high-purity unsaturated carboxylic acid amide compound and having a very low content of impurities such as organochlorine compounds. In addition, demands have also been made to provide a method without the use of aromatic hydrocarbon solvents such as toluene, because the aromatic hydrocarbon solvents may adversely affect the environment.